Web materials having both plastic and elastic properties

Abstract

An extruded web is disclosed. The extruded web can be either a nonwoven material of a films. The web comprises a plasto-elastic material where the plasto-elastic material is a combination of a first polyolefin and a second polyolefin (either a polymeric blends or a polymeric mixture). The claimed combination of polyolefins results in a material that has substantially plastic properties when a sample taken from said web is subjected to an initial strain cycle (such that the web is provided with a set of at least 30% by an initial strain cycle) and substantially elastic properties when a sample taken from the web is subjected to at least a second strain cycle.

1. An extruded web, said extruded web being selected from the group consisting of nonwovens and films and comprising a plasto-elastic material wherein said plasto-elastic material comprises a combination of an elastomeric polypropylene and a second polyolefin, said combination being selected from polymeric blends or polymeric mixtures, such that
 a) said material has substantially plastic properties when a sample taken from said web is subjected to an initial strain cycle such that said material is provided with a set of at least 30% by said initial strain cycle; and 
 b) said material has substantially elastic properties when a sample taken from said web is subjected to at least a second strain cycle. 
 
     
     
       2. An extruded web according to  claim 1  wherein said elastomeric polypropylene is a polypropylene polymer comprising crystalline isotactic blocks and amorphous atactic blocks. 
     
     
       3. An extruded web according to  claim 1  wherein said second polyolefin is a polyolefin wax. 
     
     
       4. An extruded web according to  claim 1  wherein said web is a nonwoven material. 
     
     
       5. An extruded web according to  claim 4  wherein said nonwoven material is composed of fibers, said fibers being bicomponent fibers. 
     
     
       6. An extruded web according to  claim 5  wherein said bicomponent fibers comprise an additional material having substantially elastomeric properties. 
     
     
       7. An extruded web according to  claim 5  wherein said bicomponent fibers comprise an additional material having substantially plastic properties. 
     
     
       8. An extruded web according to  claim 1  wherein said web comprises a film. 
     
     
       9. An extruded web according to  claim 8  wherein said film is a coextruded film having at least one additional layer. 
     
     
       10. An extruded web according to  claim 9  wherein said at least one additional layer comprises an additional material having substantially elastic properties. 
     
     
       11. An extruded web according to  claim 9  wherein said at least one additional layer comprises an additional material having substantially plastic properties. 
     
     
       12. An extruded web, said extruded web being selected from the group consisting of nonwovens and films and comprising a plasto-elastic material wherein said plasto-elastic material comprises a combination of:
 a) an elastomeric polypropylene; 
 b) a second polymeric material selected from the group consisting of a second polyolefin, styrenic block copolymers and combinations thereof; and 
 c) a polyolefin wax; 
 wherein said combination is selected from polymeric blends and polymeric mixtures; 
 wherein said plasto-elastic material has substantially plastic properties when a sample taken from said web is subjected to an initial strain cycle and said material has substantially elastic properties when a sample taken from said web is subjected to a second strain cycle. 
 
     
     
       13. An extruded web according to  claim 12  wherein said plasto-elastic material further comprises a second polyolefin wax. 
     
     
       14. An extruded web, said extruded web being selected from the group consisting of nonwovens and films and comprising a plasto-elastic material wherein said plasto-elastic material comprises a combination of:
 a) an elastomeric polypropylene; and 
 b) a polyolefin wax; 
 wherein said combination is selected from polymeric blends and polymeric mixtures; 
 wherein said plasto-elastic material has substantially plastic properties when a sample taken from said web is subjected to an initial strain cycle and said material has substantially elastic properties when a sample taken from said web is subjected to a second strain cycle.